Method and system to measure ecg and respiration

ABSTRACT

A method for monitoring the respiration rate of a patient includes attaching a plurality of electrocardiogram (ECG) electrodes and a pressure sensor to a patient, producing a first respiration signal based on variations detected in signals provided by the ECG electrodes attached to the patient, and producing a second respiration signal based on pressure variations detected in the pressure sensor secured to the patient. The method also includes selecting at least one of the first respiration signal and the second respiration signal based on respective signal qualities and producing a respiration rate from the selected signal. The method also includes providing indicia of the respiration rate. The method may also include displaying ECG signals with the indicia of the respiration rate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/781,400, filed on Feb. 28, 2013, which is a continuation of U.S.patent application Ser. No. 12/426,834, filed on Apr. 20, 2009, for“Method and System to Measure ECG and Respiration,” the disclosures ofwhich are fully incorporated herein by reference.

TECHNICAL FIELD

This disclosure generally relates to patient monitoring. In particular,this disclosure relates to simultaneously monitoring a patient's heartand respiratory rate.

SUMMARY

Systems and methods are provided for monitoring electrocardiogram (ECG)signals and respiration rates.

In one embodiment, a method for monitoring a respiration rate of apatient includes attaching a plurality of ECG electrodes and a pressuresensor to a patient, producing a first respiration signal based onvariations detected in signals provided by the ECG electrodes attachedto the patient, and producing a second respiration signal based onpressure variations detected in the pressure sensor secured to thepatient. The method also includes selecting at least one of the firstrespiration signal and the second respiration signal based on respectivesignal qualities and producing a respiration rate from the selectedsignal. The method also includes providing indicia of the respirationrate. In certain embodiments, the method may also include displaying ECGsignals with the indicia of the respiration rate.

In another embodiment, an integrated apparatus for measuring electricalsignals and physical movements in a patient includes a body with a topsurface and a bottom surface, an adhesive covering at least a portion ofthe bottom surface to temporarily secure the integrated apparatus to thepatient's skin, and an electrically conductive lead attachment passingfrom the top surface to the bottom surface of the body to provideelectrical communication between the patient's skin and anelectrocardiogram (ECG) lead. The integrated apparatus also includes apressure capsule secured below the top surface of the body. The pressurecapsule is responsive to changes in pressure applied thereto. Theintegrated apparatus also includes a pressure communication tubeconnected to the pressure capsule to communicate pressure variationswithin the pressure capsule to a pressure transducer.

Additional aspects and advantages will be apparent from the followingdetailed description of preferred embodiments, which proceeds withreference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top view of a pressure sensor for measuring respirationaccording to one embodiment.

FIG. 1B is a side view of the pressure sensor shown in FIG. 1A accordingto one embodiment.

FIG. 2 graphically illustrates a patient connected to a patient monitorthrough a plurality of ECG electrodes according to one embodiment.

FIG. 3A schematically illustrates a top view of an adhesive ECGelectrode with a pressure capsule secured thereunder according to oneembodiment.

FIG. 3B is a side view of the ECG electrode shown in FIG. 3A accordingto one embodiment.

FIG. 4A illustrates a top view of an integrated apparatus for measuringelectrical signals and physical movements in a patient according to oneembodiment.

FIG. 4B is a side view of the integrated apparatus shown in FIG. 4Aaccording to one embodiment.

FIG. 5 is a simplified block diagram of a system for monitoring ECGsignals and patient respiration according to one embodiment.

DETAILED DESCRIPTION

Generally, patient monitoring may include monitoring the status of apatient's heart using electrocardiogram (ECG) signals and the patient'srespiratory rate. Electrical waves cause the heart muscle to pump. Theseelectrical potentials can be sensed using electrodes attached to apatient's skin. Electrodes on different sides of the heart measure theactivity of different parts of the heart muscle. An ECG displaysvoltages between pairs of electrodes (leads) from different directions.Thus, an ECG may be used to discern overall rhythm of the heart andproblems, if any, in different parts of the heart muscle.

Several techniques may be used to obtain a respiration signal from ECGleads. For example, beat-to-beat variations may be observed in RRintervals in an ECG signal, which may be due to respiratory sinusarrhythmia. Another technique may include deriving a respiration rate bycomputing the ratio of the areas of QRS complexes in two different leadsor assessing direction changes of successive vectocardiogram loops.

Another common technique is to measure a thoracic impedance signal usingECG electrodes. This method determines the patient's respiration ratebased on an impedance measurement that is separate from the ECG signal.Thoracic impedance respiration monitoring includes injecting a highfrequency current into the ECG electrodes, and measuring the changes inimpedance due to respiration. The changes in impedance due torespiration, however, are small compared to a base impedance. Forexample, a normal base impedance may be between approximately 1 kOhm toapproximately 2 kOhms. Whereas, the change in impedance due torespiration may be on the order of only approximately 0.5 Ohms toapproximately 1 Ohm. Further, changes in impedance due to artifact(e.g., patient movement, crying, and/or feeding) are very large and mayhave the same order of amplitude as the signal of interest. Thus,thoracic impedance respiration monitoring is difficult to use forchildren or infants. In addition, the high frequency current injectedmay interfere with certain types of pacemakers and non-invasive cardiacoutput measurements that use a bio-impedance technique. Further,impedance changes due to cardiac activity may, at times, be mistakenlydetected as respiration.

Thus, in certain embodiments disclosed herein, a respiration rate ismonitored using signals obtained through ECG electrodes and a pressuresensor attached to a patient's body. In one embodiment, ECG signals areacquired via silver/silver chloride electrodes attached to the body. TheECG signals may be printed or displayed to monitor the patient's heartrhythm and/or to identify weakness in different parts of the heartmuscle. The ECG electrodes may also be used to produce an “ECGrespiration signal” that represents the patient's respiration rate. Asdiscussed above, the ECG respiration signal may be based on analysis ofthe ECG signal. In another embodiment, the ECG electrodes are used togenerate the ECG respiration signal using thoracic impedance respirationmonitoring.

The pressure sensor is used to produce a “pressure respiration signal.”For example, a pressure capsule or strain gauge may be secured to thepatient's abdomen. Pressure changes in the pressure capsule or straingauge are associated with the movement of the abdomen during breathing.Thus, pressure changes in the pressure capsule or strain gauge are usedto derive a respiration rate.

In one embodiment, one or more pressure sensors are placed under one ormore of the ECG electrodes. For example, a pressure sensor may besecured to a patient by an ECG electrode placed on a lower part of theabdomen to detect respiratory movements of the abdomen. The pressuresensor may be secured to the patient by an ECG electrode that is largeenough to hold the pressure sensor in place while making sufficientelectrical contact with the patient's skin so as to measure ECG signalsand/or thoracic impedance signals. This may be accomplished using alarge single electrode patch where the pressure sensor does not blockthe electrical connection between the electrode and the patient's skin,or a multiple electrode patch where the pressure sensor is secured tothe patient while at least one of the electrodes in the patch continuesto provide an electrical connection to the patient's skin.

In another embodiment, an integrated apparatus is attached to thepatient that measures both electrical signals and physical movements(e.g., pressure changes due to respiration). The integrated apparatusincludes both a pressure sensor and an electrode that may be attached toan ECG lead. Thus, the integrated apparatus may be used to obtain both apressure respiration signal and an ECG respiration signal.

The embodiments of the disclosure will be best understood by referenceto the drawings, wherein like elements are designated by like numeralsthroughout. In the following description, numerous specific details areprovided for a thorough understanding of the embodiments describedherein. However, those of skill in the art will recognize that one ormore of the specific details may be omitted, or other methods,components, or materials may be used. In some cases, operations are notshown or described in detail.

Furthermore, the described features, operations, or characteristics maybe combined in any suitable manner in one or more embodiments. It willalso be readily understood that the order of the steps or actions of themethods described in connection with the embodiments disclosed may bechanged as would be apparent to those skilled in the art. Thus, anyorder in the drawings or detailed description is for illustrativepurposes only and is not meant to imply a required order, unlessspecified to require an order.

Embodiments may include various steps, which may be embodied inmachine-executable instructions to be executed by a general-purpose orspecial-purpose computer (or other electronic device). Alternatively,the steps may be performed by hardware components that include specificlogic for performing the steps or by a combination of hardware,software, and/or firmware.

Embodiments may also be provided as a computer program product includinga machine-readable medium having stored thereon instructions that may beused to program a computer (or other electronic device) to perform theprocesses described herein. The machine-readable medium may include, butis not limited to, hard drives, floppy diskettes, optical disks,CD-ROMs, DVD-ROMs, ROMs, RAMs, EPROMs, EEPROMs, magnetic or opticalcards, solid-state memory devices, or other types ofmedia/computer-readable medium suitable for storing electronicinstructions.

FIG. 1A is a top view of a pressure sensor 100, and FIG. 1B is a sideview of the pressure sensor 100 used to acquire a pressure respirationsignal according to one embodiment. The pressure sensor 100 includes apressure capsule 110 and a pressure communication tube 112. The pressurecapsule 110 may include a hollow bladder or balloon. In one embodiment,the pressure capsule 110 has a diameter of approximately 18 millimetersand a height of approximately 4 millimeters. An artisan will understandfrom the disclosure herein, however, that these measurements areprovided by way of example only and that the pressure capsule 110 may besubstantially smaller or substantially larger depending on theparticular application. Suitable pressure capsules 110 and pressurecommunication tubes 112 are available from Viomedix Limited of GordonRoad, Buxted, Uckfield, East Sussex TN22 4LH (UK).

In one embodiment, the pressure capsule 110 comprises a plastic materialconfigured to respond to respiration movements when secured to apatient. For example, the pressure capsule 110 may be attached to theabdomen or chest of the patient, and breathing may cause the pressureinside the pressure capsule 110 to change. The plastic material of thepressure capsule 110 may be very thin, and the pressure capsule 110 mayinclude therein a biasing element such as a sponge or other material tocounteract the movement of the patient.

A proximal end 113 of the pressure communication tube 112 is connectedto the pressure capsule 110. The pressure communication tube 112 ishollow and may include a plastic material. A distal end 114 of thepressure communication tube 112 is configured for connection, asdiscussed in detail below, to a pressure measurement channel of apatient monitor. For example, the distal end 114 of the pressurecommunication tube 112 may be connected to an invasive blood pressureport of the patient monitor.

In one embodiment, the pressure communication tube 112 includes athicker plastic material than that used for the pressure capsule 110such that pressures applied to the pressure communication tube 112during normal operation do not substantially interfere with the pressurechanges detected by the pressure capsule 110. The pressure within thepressure sensor 100 is based on the volume of air within both thepressure capsule 110 and the pressure communication tube 112. Thus, thepressure capsule 110 material is selected to be more sensitive tomovements than the material of the pressure communication tube 112.Further, a longer pressure communication tube 112 may cause air pressurechanges in the pressure capsule 110 to become less detectable. Thus, incertain embodiments, the length of the pressure communication tube 112is selected so as to provide adequate sensing of pressure changesapplied to the pressure capsule 110 during respiration.

When the pressure capsule 110 is held in place against the abdominalwall of a patient, abdominal movement during respiration results incompression and decompression of the pressure capsule 110. Compressionand decompression of the pressure capsule 110 causes a pressure changeinside the pressure capsule 100. These pressure changes are communicatedto the pressure measurement channel of the monitor through the pressurecommunication tube 112. As discussed below, the pressure measurementchannel of the monitor includes a pressure transducer that convertschanges in pressure into an electrical signal. This pressure signal isrepresentative of respiration (e.g., it is the pressure respirationsignal), and may be used to derive a respiration rate and/or determine acessation of breathing. In one embodiment, the patient monitor includessoftware modifications on the pressure channel to derive the respirationrate information.

FIG. 2 graphically illustrates a patient 210 connected to a patientmonitor 214 through a plurality of ECG electrodes 216, 218, 220, 222,224 according to one embodiment. The ECG electrodes 216, 218, 220, 222,224 are connected to respective ECG lead channels 225 (five shown) ofthe patient monitor 214 through respective ECG leads 227 (five shown).The patient monitor 214 includes a display 226 for displaying an ECGsignal 228 provided through the ECG leads 227. While the example shownin FIG. 2 illustrates a 5-lead arrangement, an artisan will recognizefrom the disclosure herein that other lead systems may also be usedincluding, for example, a 12-lead system, a 6-lead system, or a 3-leadsystem.

As shown in FIG. 2, in one embodiment, one of the ECG electrodes 222secures a pressure sensor 100 to the patient. For example, the pressurecapsule 110 shown in FIGS. 1A and 1B may be placed under the electrode222, or as discussed below, may be integrated as part of the electrode222. In FIG. 2, the pressure capsule 110 is placed under or integratedwith the ECG electrode 222 placed on the lower abdomen of the patient210. However, an artisan will understand from the disclosure herein thatthe pressure capsule 110 may be placed under or integrated with adifferent ECG electrode 216, 218, 220, 222, 224, and/or that more thanone pressure sensor 100 may be used.

The pressure communication tube 112 extends from the ECG electrode 222to a pressure measurement channel 230 of the patient monitor 214. Thepressure measurement channel 230 may include a pressure transducer (notshown) to convert pressure changes in the pressure sensor 100 to anelectrical pressure respiration signal related to the patient'srespiration rate.

In addition to providing measurements for the ECG signal 228, certainpairs of ECG electrodes (typically ECG electrodes 216 and 222, or 216and 218) are also used to determine an ECG respiration signal related tothe patient's respiration rate. As discussed in detail below, thepatient monitor 214 analyzes the ECG respiration signal and the pressurerespiration signal to determine the patient's respiration rate. Thedisplay 226 may display a waveform 232 representative of the determinedrespiration. The waveform 232 may include a sequence of times(represented by way of example in FIG. 2 as a series of peaks) at whichthe patient 210 breathes. In addition, or in other embodiments, thedisplay 226 may display a numerical value (not shown) of the determinedrespiration rate.

FIG. 3A schematically illustrates a top view of an adhesive ECGelectrode 222 with the pressure capsule 110 placed thereunder accordingto one embodiment.

FIG. 3B is a side view of the ECG electrode 222 with the pressurecapsule 110 placed thereunder. The ECG electrode 222 may include a body310, an electrically conductive lead attachment 312 passing through aninsertion hole 314 in the body 310, an electrically conductive gel 313for providing an electrical connection between the lead attachment 312and the patient's body 210, and an adhesive 316 for attaching the ECGelectrode 222 to the patient's body 210. As an artisan will understandfrom the disclosure herein, the adhesive 316 may be electricallyconductive in certain embodiments to reduce the impedance of the ECGelectrode. The lead attachment 312 is configured to connect to an ECGlead 227 for communicating ECG signals to the patient monitor 214. Forillustrative purposes, FIG. 3B shows the pressure capsule 110 placedunder the ECG electrode 222 so as to be secured by the body 310 and theadhesive 316 against the skin of the patient 210.

In another embodiment, an ECG electrode and a pressure sensor areintegrated into a single apparatus. For example, FIG. 4A illustrates atop view of an integrated apparatus 400 for measuring electrical signalsand physical movements in a patient according to one embodiment. FIG. 4Bis a side view of the integrated apparatus 400 according to oneembodiment. The integrated apparatus 400 includes a body 310 comprisinga flexible, non-electrically conducting material. The body 310 includesan ECG portion 410 and a pressure portion 412. The ECG portion 410includes an electrically conductive lead attachment 312 passing throughan insertion hole 314 in the body 310. As discussed above, the leadattachment 312 is configured to make electrical contact with the patient210 (e.g., through an electrically conducting gel 313 shown in FIG. 3).The pressure portion 412 includes a pressure sensor 100. The pressuresensor 100 may include a pressure capsule 110 embedded under a topsurface 414 of the body 310 and a pressure communication tube 112 thatextends from the pressure capsule 110 through an opening in the topsurface 414 of the body. The pressure capsule 110 may be glued orotherwise affixed to the body 310.

The integrated apparatus 400 includes an adhesive 316 for attaching theintegrated apparatus 400 to the skin of the patient 210. As discussedabove, in certain embodiments the adhesive 316 may be electricallyconductive. The integrated apparatus 400 may also includes a peel offbacking 416 that may be removed by the user to expose the adhesive 316when the integrated apparatus 400 is attached to a patient 210.

As shown in FIG. 4A, the body 310 of the integrated apparatus 400 may beshaped so as to allow the user to apply the integrated apparatus 400 tothe skin of the patient 210 with sufficient separation between the ECGportion 410 and the pressure portion 412 of the integrated apparatus400. Thus, during use, the electrically conducting lead attachment 312and the pressure capsule 110 are both properly secured to the patient210, and the ECG leads 227 and pressure communication tube 112 do notinterfere with each other. An artisan will understand from thedisclosure herein, however, that the body 310 of the integratedapparatus 400 may have any shape. In certain embodiments, the integratedapparatus 400 is disposable.

FIG. 5 is a simplified block diagram of a system 500 for monitoring ECGsignals and patient respiration according to one embodiment. The system500 includes a plurality of ECG leads 227 electrically connected to areceiver component 512 that is in communication with a memory device514, an interface component 516, an ECG component 530, and a displaydevice 538. The ECG leads 227 are configured to connect to respectiveECG electrodes attached to a patient 210 (see FIG. 2) to detect ECGsignals.

The receiver component 512 may include, for example, an amplificationcomponent 522 to amplify the ECG signals detected by the leads 227, afiltering component 524 to eliminate undesirable noise from the ECGsignals, and an analog-to-digital (A/D) converter 526 to provideconverted ECG signals through a system bus 528 to the memory device 514,the interface component 516, the ECG component 530, and the displaydevice 538.

As shown in FIG. 5, the system 500 also includes an ECG respirationcomponent 532 connected to the ECG leads 227. The ECG respirationcomponent 532 produces an ECG respiration signal based on signalsmeasured using the ECG leads 227. The ECG respiration component 532provides the ECG respiration signal to an ECG respiration signal qualitycheck component 533. The ECG respiration signal quality check component533 runs a quality test on the ECG respiration signal. In oneembodiment, the ECG respiration component 532 is configured to determinethe thoracic impedance respiration of the patient. Those skilled in theart will recognize that the ECG respiration component 532 may determinethe thoracic impedance respiration of the patient using known techniquesincluding, for example, injecting a high frequency current into one ofthe ECG leads 227 and measuring the high frequency current detected onone or more of the other ECG leads 227. As discussed above, the ECGrespiration component 532 in other embodiments may produce ECGrespiration signals based on changes to ECG signals due to respiration.

The system 500 also includes a pressure respiration component 534connected to the pressure communication tube 112. The pressurerespiration component 534 produces a pressure respiration signal. Thepressure respiration component 534 includes a pressure transducer (notshown) for converting a pressure signal from the pressure sensor 100 toan electrical signal (pressure respiration signal). The pressurerespiration component 534 provides the pressure respiration signal to apressure respiration signal quality check component 535. The pressurerespiration signal quality check component 535 runs a quality test onthe pressure respiration signal.

The ECG respiration signal quality check component 533 and the pressurerespiration signal quality check component 535 may use a variety ofdifferent techniques for artifact and/or noise detection. For example,and not by way of limitation, the ECG respiration signal quality checkcomponent 533 and the pressure respiration signal quality checkcomponent 535 may use one or more of the following methods: (1) theadaptive moving average filtering, variable length peak detectionwindow, and comparison of detected peaks to an adaptive threshold todistinguish noise peaks from respiration signal peaks taught by R.Lukocius, J. A. Virbalis, J. Daunoras, and A. Vegys, “The RespirationRate Estimation Method based on the Signal Maximums and MinimumsDetection and the Signal Amplitude Evaluation,” Electronics andElectrical Engineering, Kaunaus: Technologija, 2008, No. 8 (88), pp.51-54; (2) the signal abnormality index algorithm taught by J. X. Sun,A. T. Reisner, and R. G. Mark, “A Signal Abnormality Index for ArterialBlood Pressure Waveforms,” Computers in Cardiology, 2006, vol. 33, pp.13-16; (3) the correlation algorithm taught by G. D. Clifford, A.Aboukhalil, J. X. Sun, W. Zong, B. A. Janz, G. B. Moody, and R. G. Mark,“Using the Blood Pressure Waveform to Reduce Critical False ECG Alarms,”Computers in Cardiology, 2006, vol. 33, pp. 829-832; (4) the signalquality metrics taught by Q. Li, R. G. Mark, and G. D. Clifford, “RobustHeart Rate Estimation from Multiple Asynchronous Noisy Sources usingSignal Quality Indices and a Kalman Filter,” IOP PhysiologicalMeasurement, January 2008, 29(1), pp. 15-32; (5) the ECG artifactdetection taught by J. A. Jiang, C. F. Chao, M. J. Chiu, and R. G. Lee,“An Automatic Analysis Method for Detecting and Eliminating ECGArtifacts in EEG,” Computers in Biology and Medicine, November 2007,Vol. 37, Issue 11, pp. 1660-1671; and/or (6) the noise and artifactdetection taught by dePinto in U.S. Pat. No. 5,983,127. Artisans willrecognize from the disclosure herein that the noise and artifactdetection in the physiological signals discussed in the referenceslisted above may be applied to the respiration signals discussed herein.Further, artisans will recognize from the disclosure herein that the ECGrespiration signal quality check component 533 and the pressurerespiration signal quality check component 535 may use other known noiseand/or artifact detection methods to determine the quality of therespective respiration signals.

The system 500 also includes respiration decision logic 536 to determinethe patient's respiration rate based on one or both of the ECGrespiration signal and the pressure respiration signal. The ECGrespiration signal quality check component 533 provides the ECGrespiration signal and an indication of the ECG respiration signal'squality to the respiration decision logic 536. Similarly, the pressurerespiration signal quality check component 535 provides the pressurerespiration signal and an indication of the pressure respirationsignal's quality to the respiration decision logic 536. Based on therespective indications of signal quality, the respiration decision logic536 determines whether to use the ECG respiration signal, the pressurerespiration signal, or a combination of the ECG respiration signal andthe pressure respiration signal to determine the patient's respirationrate.

For example, the ECG respiration signal quality check component 533 mayindicate that the ECG respiration signal is noisy or includes excessiveartifacts, and the pressure respiration signal quality component checkcomponent 535 may indicate that the pressure respiration signal has anacceptable quality. In such a case, the respiration decision logic 536is configured to use the pressure respiration signal to determine thepatient's respiration rate. Similarly, if the ECG respiration signal hasan acceptable quality and the pressure respiration signal has a poorquality, the respiration decision logic 536 uses the ECG respirationsignal to determine the patient's respiration rate.

In one embodiment, if both the ECG respiration signal and the pressurerespiration signal have an acceptable quality, then the respirationdecision logic 536 may select either respiration signal to determine thepatient's respiration rate. In another embodiment, if both respirationsignals have an acceptable quality, then the respiration decision logic536 may select the respiration signal with the highest quality todetermine the patient's respiration rate. In another embodiment, if boththe ECG respiration signal and the pressure respiration signal have anacceptable quality, both respiration signals may be used to determinethe patient's respiration rate. For example, the respiration ratesderived from both respiration signals may be averaged. In certain suchembodiments, the respiration rates derived from both respiration signalsare averaged if the difference between the two respiration rates areless than 10% to 15%. In one embodiment, if neither the ECG respirationsignal nor the pressure respiration signal has an acceptable quality,then the patient's respiration rate is not determined and/or displayeduntil an acceptable respiration signal is acquired from either source.

The respiration decision logic 536 is connected to the bus 528 such thatit may provide the derived respiration rate and/or the waveform 228 tothe memory device 514, the interface component 516, and/or the displaydevice 538. In one embodiment, the system 500 allows a clinician toselect data corresponding to one or more of the leads for display as anECG signal on a display device 538. The system 500 also allows aclinician to display the patient's respiration rate on the displaydevice 538 and/or the waveform 232 representing the patient'srespiration.

In certain embodiments, the system 500 also includes a respiration alarm540 that compares the respiration rate produced by the respirationdecision logic 536 to one or more respiration rate threshold condition.For example, a high respiration rate threshold and a low respirationrate threshold may be provided. If the derived respiration rate equalsor exceeds the high respiration rate threshold, the respiration alarm540 provides indicia of an alarm condition. Similarly, if the derivedrespiration rate equals or falls below the low respiration ratethreshold, the respiration alarm 540 provides indicia of an alarmcondition. To provide the alarm indicia, for example, the respirationalarm 540 may display an alarm symbol (not shown) on the display device538 and/or provide an audible alarm.

The ECG component 530, the ECG respiration component 532, the pressurerespiration component 534, and the respiration decision logic 536, mayinclude a special purpose processor configured to perform the processesdescribed herein. In another embodiment, these components may include ageneral purpose processor configured to execute computer executableinstructions (e.g., stored in a computer-readable medium (such as thememory device 514) to perform the processes described herein. Inaddition or in other embodiments, these devices may be connected to ahost computer (not shown) having a display device of its own. The hostcomputer may include computer executable instructions for forming theprocesses described herein. Those computers may be used in certainembodiments, for example, to provide remote patient monitoring.

It will be understood by those having skill in the art that many changesmay be made to the details of the above-described embodiments withoutdeparting from the underlying principles of the invention. The scope ofthe present invention should, therefore, be determined only by thefollowing claims.

What is claimed is: 1-25. (canceled)
 26. A patient monitoring systemcomprising: an ECG respiration component configured to communicate witha plurality of ECG lead channels to produce a first respiration signalbased on variations detected in the ECG lead channels; a pressurerespiration component configured to detect pressure variations in apressure measurement channel and to produce a second respiration signalbased on the pressure variations; respiration decision logic configuredto compare respective signal qualities of the first and secondrespiration signals and to select at least one of the first and secondrespiration signals based on the respective signal qualities to producea respiration rate; and a display device to provide indicia of therespiration rate.
 27. The system of claim 26, wherein the variationsdetected in the ECG lead channels comprise variations in thoracicimpedance during patient respiration.
 28. The system of claim 27,wherein the ECG respiration component is configured to: produce animpedance signal between two or more ECG electrodes; and produce thefirst respiration signal based on variations in the impedance signal.29. The system of claim 26, wherein the ECG lead channels are configuredto receive ECG signals related to electrical waves that cause thepatient's heart muscle to pump, and wherein the variations detected inthe ECG lead channels comprise variations in the ECG signalscorresponding to patient respiration.
 30. The system of claim 26,further comprising an ECG electrode to detect ECG signals related toelectrical waves that cause the patient's heart muscle to pump, the ECGelectrode configured and sized to temporarily secure the pressure sensorto the patient.
 31. The system of claim 26, further comprising anintegrated apparatus for measuring electrical signals and physicalmovements in the patient, the integrated apparatus comprising: a bodycomprising a top surface and a bottom surface; an electricallyconductive adhesive covering at least a portion of the bottom surface totemporarily secure the integrated apparatus to the patient's skin; anelectrically conductive lead attachment passing from the top surface tothe bottom surface of the body to provide electrical communicationbetween the patient's skin and one of the ECG lead channels; a pressurecapsule secured below the top surface of the body, the pressure capsuleresponsive to changes in pressure applied thereto; and a pressurecommunication tube connected to the pressure capsule to communicatepressure variations within the pressure capsule to the pressuremeasurement channel.
 32. The system of claim 31, wherein the integratedapparatus is disposable.
 33. The system of claim 26, further comprising:a first respiration signal quality check component to determine a firstsignal quality corresponding to the first respiration signal; and asecond respiration signal quality check component to determine a secondsignal quality corresponding to the second respiration signal, whereinthe respiration decision logic is configured to produce the respirationrate based on the first signal quality and the second signal quality.34. The system of claim 26, further comprising a respiration alarm to:compare the respiration rate produced by the respiration decision logicto a respiration rate threshold condition; and provide indicia of analarm based on the comparison.
 35. The system of claim 26, wherein thedisplay device displays a numerical value of the respiration rate. 36.The system of claim 26, wherein the display device displays a waveformrepresenting the sequence of times corresponding to the respirationrate.
 37. A computer readable storage medium having stored thereonexecutable instructions that, when executed by a processor of anelectronic device, cause the electronic device to: communicate with aplurality of ECG lead channels to produce a first respiration signalbased on variations detected in the ECG lead channels; detect pressurevariations in a pressure measurement channel and produce a secondrespiration signal based on the pressure variations; and comparerespective signal qualities of the first and second respiration signalsand select at least one of the first and second respiration signalsbased on the respective signal qualities to produce a respiration rate;and indicate the respiration rate to a user.
 38. The computer readablestorage medium of claim 37, wherein producing the first respirationsignal comprises: producing an impedance signal between two or more ECGelectrodes; and detecting variations in the impedance signalcorresponding to patient respiration.
 39. The computer readable storagemedium of claim 37, wherein producing the first respiration signalcomprises: receiving ECG signals related to electrical waves that causethe patient's heart muscle to pump; and detecting variations in the ECGsignals corresponding to patient respiration.
 40. The computer readablestorage medium of claim 37, wherein selecting at least one of the firstrespiration signal and the second respiration signal based on respectivesignal qualities comprises: determining a first signal qualitycorresponding to the first respiration signal; and determining a secondsignal quality corresponding to the second respiration signal.
 41. Thecomputer readable storage medium of claim 40, wherein selecting at leastone of the first respiration signal and the second respiration signalcomprises: selecting the highest quality among the first signal qualityand the second signal quality.
 42. The computer readable storage mediumof claim 40, wherein selecting at least one of the first respirationsignal and the second respiration signal comprises: determining thatboth the first signal quality and the second signal quality are at anacceptable level; and based on the determination, randomly selectingeither the first respiration signal or the second respiration signal.43. The computer readable storage medium of claim 40, wherein selectingat least one of the first respiration signal and the second respirationsignal comprises: determining that both the first signal quality and thesecond signal quality are at an acceptable level; determining a firstrespiration rate from the first respiration signal; determining a secondrespiration rate from the second respiration signal; and averaging thefirst respiration rate and the second respiration rate.
 44. The computerreadable storage medium of claim 37, wherein the instructions furthercause the electronic device to: compare the respiration rate to arespiration rate threshold condition; and provide indicia of an alarmbased on the comparison.
 45. The computer readable storage medium ofclaim 37, wherein indicating the respiration rate comprises numericallydisplaying the respiration rate on a display device of a patientmonitor.
 46. The computer readable storage medium of claim 37, whereinindicating the respiration rate comprises displaying a graphicalwaveform representing the sequence of times corresponding to therespiration rate on a display device of a patient monitor.